求行列式第一行x^2+1 xy xz 第二行xy y^2+1 yz 第三行xz yz z^2+1
求行列式第一行x^2+1 xy xz 第二行xy y^2+1 yz 第三行xz yz z^2+1
(2X+Z-Y)/(X^2-XY+XZ-YZ)-(Y-Z)/(X^2-XY-XZ+YZ)
求(2X+Z-Y)/(X^2-XY+XZ-YZ)-(2X+Y+Z)/(X^2+XY+XZ+YZ)
若x/2=1/y=z/3,且xy+xz+yz=99,求4x^2-2xz+3yz-9y^2的值.
设x,y,z∈R+,xy+yz+xz=1,证明不等式:(xy)^2/z+(xz)^2/y+(yz)^2/x+6xyz≥x
xy/x+y=1,yz/y+z=2,xz/x+z=3求x,y
x-3=y-2=z-1,求x^2+y^2+z^2-xy-yz-xz的值
已知x+y+z=1,xy+yz+xz=0,求x^2+y^2+z^2的值.
已知x+y+z=1,x²+y²+z²=2求xy+yz+xz的值
XYZ-XY-XZ+X-YZ+Y+Z-1
xyz-xy-xz+x-yz+y+z-1因式分解
化简(2x-y-z/x^2-xy-xz+yz)+(2y-x-z/y^2-xy-yz+xz)+(2x-x-y/z^2-xz